Xfly Models B1B Bomber 70mm

[F106DeltaDart]

Good report RudyD54 thanks!

I successfully maidened mine over the weekend. I'll post the video later today. I actually did connect the XT90 to the EC5. I wrapped some Gorilla Tape around the connectors and it held fine after two sorties. Although I admit it was not ideal and a bit risky. The connectors were WARM after the flights. I got my adapter so I will be using those moving forward. The maiden was decent although I forgot to retract my takeoff flaps which would explain why she felt sluggish at full throttle (smacks forehead). Landing is a breeze. You could probably dead stick her in. When I swept the wings it felt wonky a bit. Seemed to not want to track straight and bank to the left so I quickly brought the wings back out.

The wings had a ridiculous dihedral so I was hoping to get someone's advice...When you mount that metal bracket piece to the pivot point mech, did you use 16mm length screws for all of them? The manual confused me...Looks like two are a 6mm and the other is 16mm? Perhaps that would explain the dihedral? Not enough "meat" going into the holes?

Congrats Aros! On mine, following Jeremy's build video, I used the 16mm screw in the center and the 6mm screws on the flanges. I didn't have any noticeable dihedral on my (albeit brief) first/last flight.

[GliderGuy]

The dihedral reminds me of the Concordia sailplane….Aros’ B-1B doesn’t look right.

Congrats on the maiden!

-GG

[jetpltrich]

Should be like this.

[Aros]

Congrats Aros! On mine, following Jeremy's build video, I used the 16mm screw in the center and the 6mm screws on the flanges. I didn't have any noticeable dihedral on my (albeit brief) first/last flight.

Well drat, that's what I did too which means it's something else and I have no idea what it could be. I'll have to take the wings apart and investigate.

[F106DeltaDart]

Well drat, that's what I did too which means it's something else and I have no idea what it could be. I'll have to take the wings apart and investigate.

I wonder if you got a QC fail where the factory sealed the wings up without putting in a spar.. it’s the only explanation I can think of that would result in that.

[F106DeltaDart]

Well drat, that's what I did too which means it's something else and I have no idea what it could be. I'll have to take the wings apart and investigate.

The other thing to check would be the bearings embedded into the wings. They may have missed adding the bearings on the bottom side of the wings. Having only one set would result in something looking very similar.

[Aros]

Eeep!! I sure hope there's spars! But it does look like (in the video) there are none?? Holy catfish. I'll check for sure along with the bearings...Thanks!

Here's the video:

[kallend]

Eeep!! I sure hope there's spars! But it does look like (in the video) there are none?? Holy catfish. I'll check for sure along with the bearings...Thanks!

Here's the video:

It's hard to see from the video but it looks to me during the take-off roll that the dihedral is coming from the wing root area (the pivots), and is not flexing in the wing itself as would be expected if a spar was missing. At 0:09 the wing itself looks quite straight but it is definitely angled up from the root.

[Coconut]

The wing is on backwards .

[Coconut]

BBBBAD BAD, BAD to the SPAR!!!

[Elbee]

Eeep!!

Aros, there is nothing good going on there except the wings stayed onboard. Cheeez und Krakers, Bro. Best, LB

[Evan D]

I’ll say it once more XT and EC are not compatible and if you decide to plug one into the other it’s a stupid decision. Kallend said in a pinch you can spread the pin to make a better connection but DON’T DO IT. In the picture are two types of pins used, these are both EC5 pins. The one on the left is what he’s saying to spread and yes I guess if you did it would make a connection but it’s just not designed to be used that way. I can’t believe a professor actual even suggested it. What’s next, missing that machine screw to hold your wings on, use a wood screw, it’s close enough?

XT90 and EC5 are not compatible. The pin on the XT is 4.5mm and the tube on the EC is 5.0mm. Don’t do it.

[kallend]

I’ll say it once more XT and EC are not compatible and if you decide to plug one into the other it’s a stupid decision. Kallend said in a pinch you can spread the pin to make a better connection but DON’T DO IT. In the picture are two types of pins used, these are both EC5 pins. The one on the left is what he’s saying to spread and yes I guess if you did it would make a connection but it’s just not designed to be used that way. I can’t believe a professor actual even suggested it. What’s next, missing that machine screw to hold your wings on, use a wood screw, it’s close enough?

Considering that many people just plug the EC into the XT without doing anything whatsoever to improve the fit, I think my "in a pinch" suggestion is a safer way to go. I realize the USN wouldn't approve. I didn't suggest it as a permanent solution.

But you are correct, you SHOULD either change one or the other, or use an adapter (and I have seen some very flaky adapters too).

[Evan D]

I’ve seen the wood screw example as well as people cutting off the mismatched adapters, twisting the wires together and putting some tape on it and fly… seen some other bad practices too.

I think Aros was lucky between the wings not being on right and the connectors… be interesting to find out what was going on with the wings.

[GliderGuy]

Good points all. I’d like to add that with a huge number of connect/disconnect operations, the screen on the right side type evaporates. Each tiny connection spark blows away screen material. Eventually, the spring screen totally fails. These types of connectors should be routinely inspected with a bright light.

While not without issues, I have changed all my EDFs over to the split barrel type. I have had 2 spring/screen connectors end up with disintegrated spring screens. Luckily found before flight on one and by a post flight bubble of melted plastic connector on another.

-GG

[Evan D]

I still use T connectors on most of my planes

[Aros]

The connector issue: They connect perfectly fine. Yes a quick spark but other than that there was no resistance, no issue. It's funny how some people will claim it's stupid and others will say it's fine in a pinch. I've heard both sides. I will simply say it may not have been the smartest choice but in the end it did just fine. However, clearly it was a very temporary solution.

Now the WING issue is the real conundrum. I need to get to the bottom of that before ANY other flight ensues.

[Evan D]

I see people driving on the highway with those tiny spare tires too. Fine.

[Aros]

LOL! I hear ya my friend. Trust me, I know I was taking a big risk. Sometimes ya just get lucky.

[Evan D]

So the big question is what’s the new FL plane???